Preheat the oven to 180°C.
Fry celery, carrots, and onion in olive oil for 15 minutes until softened, then add garlic and rosemary for 2 minutes.
Add beef and pork mince and cook until the meat liquid is fully absorbed.
Pour in 400ml of red wine and cook for 45 minutes until evaporated.
Add tomatoes and stock, then simmer uncovered for two hours, seasoning to taste.
Infuse milk with bay leaves, onion, and nutmeg by bringing it gently to a boil.
Melt 50g butter in a pan, whisk in flour for 2 minutes, then gradually incorporate the infused milk to form a sauce.
Blanch pasta sheets in salted boiling water for 3 minutes.
Layer béchamel, pasta, mozzarella, parmesan, pepper, and ragu in a dish three times.
Dot the top with 2 tablespoons of butter and bake for 30 minutes until golden-brown.